A lithium ion battery is a rechargeable battery and has advantages of high energy density, high power density, long cycle life and long storage life, etc., and thus is widely applied in portable electronic devices such as cell phones and notebook PCs, and electric transportation vehicles such as electric vehicles and electric bicycles.
An electrode member of the lithium ion battery is generally made of metal material, for example, the positive electrode member is generally made of aluminum foil and the negative electrode member is generally made of copper foil. However, the aluminum foil (or copper foil) readily forms burrs when being punctured by the nail in the nailing test, and the burrs directly lap on the negative electrode member (or the positive electrode member), which results in internal short circuit in the positive electrode member and the negative electrode member, causing fire or explosion of the lithium ion battery.